Sant'Andrea is a small island in the Venetian Lagoon, northern Italy.

It houses the Forte di Sant'Andrea [it], a large fortress built in the 16th century to defend Venice. Sant'Andrea constitutes a prolongation of the island of Vignole, from which it is separated by a narrow channel, towards the Porto di Lido-San Nicolò [it] on the Lido, between Venice's Island and the island of Sant'Erasmo.